Panarctic Flora

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500709 Saxifraga paniculata Mill.

2n= 28 (4x). - Europe (N, C) - Numerous reports, probably mostly for subsp. paniculata.

Geography: North American (NE) - amphi-Atlantic - European.

Notes: Zhmylev: Saxifraga paniculata is an amphi-Atlantic, arctic-alpine species, widely distributed in the mountains of western, central, and eastern Europe. Arctic plants differ from the typical race by longer and different testa papillas and thicker raphe, marking the place of capsule dehiscence. American botanists regard arctic plants as S. paniculata subsp. neogaea (see Butters 1944). However, the variability of S. paniculata is fairly large so that the differences may not have any taxonomic value.

Elven: Hultén and Fries (1986) assigned the Canadian plants to S. paniculata subsp. neogaea, the Greenland and Iceland ones to subsp. paniculata. Butters (1944) assigned also the Greenland and Iceland plants to subsp. neogaea as did Jørgensen et al. (1958: 76). In a molecular study (Reisch 2008), S. paniculata divided on three branches corresponding to three previously proposed races: subsp. paniculata in the central and southern European mountains and also including the isolated southwestern Norwegian population group, subsp. cartilaginea in the Caucasus, and subsp. neogaea in northeastern North America, Greenland, Iceland, and including the two isolated northern Norwegian population groups. However, as one of the two northern Norwegian population groups was given a subspecific name quite early, the priority name for the trans-Atlantic race is subsp. laestadii rather than subsp. neogaea. Brouillet and Elvander (2009b) discussed the results of Reisch but without accepting races. Additional separating characters have been proposed in, e.g., panicle shape (open in subsp. paniculata vs. compact in subsp. laestadii), flower shape (open vs. more bell-shaped), and stem leaves (subpatent vs. more appressed). We accept the northern and amphi-Atlantic plant as a subspecies.

Higher Taxa